<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>this</title>
</head>
<script>
    class Point {
        constructor(x, y) {
            this.x = x;
            this.y = y
        }

        show() {
            console.log(this);
        }
        show2() {
            return () => {
                console.log(this);
            }
        }
        show3(){
            console.log(this);
        }
    }

    (function () {
        var p1 = new Point(1, 2);
        p1.show();
        var fn = p1.show2();
        fn();
        p1.show3.call({m:1});

    })();
</script>

<body>

</body>

</html>